This proposal requests a Finnigan ProteomeX LTQ workstation, an integrated chromatography electrospray ionization linear ion trap mass spectrometer to bring our Basic and Translational Proteomics Center / Shared Research Facility's analytical capability up to state-of-the-art and to increase our capacity to meet the ever increasing volume and intensity of work by our investigators. This request is essential to support our ongoing research programs and to stimulate and enable new collaborative research initiatives on protein identification, posttranslational modification characterization, gene discovery, and functional proteomics. Currently, there is no ESI-LTQ linear ion trap mass spectrometer at the Mount Sinai Medical Center (Hospital and School of Medicine), which provides a fundamental reason for this request. The ProteomeX LTQ workstation is requested in replace of our aged Finnigan LCQ classic mass spectrometer which breaks down so frequently that it seriously affects the on-going research projects. The requested ProteomeX LTQ linear ion trap mass spectrometer will be housed in our Basic and Translational Proteomics Center. The purchase of the ProteomeX LTQ linear ion trap mass spectrometer is fundamental to the continuing expansion and enhancement of the basic research programs and translational proteomics research for human disease on the Mount Sinai campus. As described in this application, over 22 NIH-funded investigators from 10 different departments and two NIH-funded investigators from neighboring institutes have specific needs for this mass spectrometer, which will be a shared research resource. Indeed, due to the lack of an highly sensitive and high throughput proteomics instrument on campus, some of these research projects are seriously delayed or compromised. Thus, the purchase of the ProteomeX LTQ system will have a major impact on the research capabilities at our institution. [unreadable] [unreadable]